Kepler-37

Kepler-37 is a G-type main-sequence star located in the constellation Lyra, approximately 209 light-years (64 parsecs) from Earth. The star is notable for hosting at least three confirmed exoplanets, including Kepler-37b, which, at the time of its discovery, was the smallest exoplanet known to orbit a Sun-like star.

Stellar Characteristics:

Kepler-37 is somewhat smaller and cooler than our Sun. Its mass is about 80% of the Sun's mass, and its radius is approximately 77% of the Sun's radius. The star's effective temperature is around 5,417 K, making it a G9V star according to the Morgan-Keenan spectral classification system. Kepler-37 has an estimated age of around 6 billion years.

Planetary System:

The Kepler-37 planetary system currently includes three confirmed planets discovered via the transit method by the Kepler Space Telescope. These planets are:

• Kepler-37b: The innermost planet, roughly the size of our Moon (about 0.3 Earth radii). It orbits Kepler-37 very closely, with a period of approximately 13 days. Due to its small size and proximity to the star, Kepler-37b is likely a rocky, airless world unsuitable for life as we know it.
• Kepler-37c: A slightly larger planet, about twice the size of Earth (around 2.01 Earth radii). It orbits Kepler-37 with a period of roughly 21 days.
• Kepler-37d: The outermost known planet in the system, about three times the size of Earth (around 3.06 Earth radii). It orbits Kepler-37 with a period of approximately 40 days.

The relatively close proximity of these planets to each other and to their star has made the Kepler-37 system a subject of interest for studying planetary formation and system dynamics. The discovery of Kepler-37b, in particular, highlighted the capabilities of the Kepler mission to detect very small exoplanets.